Notices
Modified JK Tech Tech related bulletin board forum regarding subjects such as suspension, tires & wheels, steering, bumpers, skid plates, drive train, cages, on-board air and other useful modifications that will help improve the performance and protection of your Jeep JK Wrangler (Rubicon, Sahara, Unlimited and X) on the trail.

PLEASE DO NOT START SHOW & TELL TYPE THREADS IN THIS FORUM
Sponsored by:
Sponsored by:

Thoughts on shimmy

Thread Tools
 
Old 05-03-2016, 07:50 PM
  #1  
JK Freak
Thread Starter
 
phljeeper's Avatar
 
Join Date: Aug 2009
Location: Philly Suburbs
Posts: 950
Likes: 0
Received 8 Likes on 4 Posts
Default Thoughts on shimmy

I have a 2015 two door with 2.5" Rock Krawler max travel with 35" trail grapplers. Rides great at city speeds and on the highway up to about 65. At 70 I get a shimmy. It feels like a tire balance issue but I have just had them re balanced and all good. Thoughts on what to check next?
Old 05-03-2016, 10:27 PM
  #2  
JK Junkie
 
sa29560's Avatar
 
Join Date: Apr 2010
Location: - - Jeep-topia - -
Posts: 2,123
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by phljeeper
I have a 2015 two door with 2.5" Rock Krawler max travel with 35" trail grapplers. Rides great at city speeds and on the highway up to about 65. At 70 I get a shimmy. It feels like a tire balance issue but I have just had them re balanced and all good. Thoughts on what to check next?
Work your way up. Check ball joints, tie rod ends, and drag link ends, track bar at frame and axle, play in unit bearings, bad u joints, torque on all bolts in control arms.

You running stock drive shaft?
Old 05-04-2016, 12:59 AM
  #3  
JK Super Freak
 
Biginboca's Avatar
 
Join Date: Jan 2011
Location: Delray Beach, FL
Posts: 1,127
Likes: 0
Received 3 Likes on 3 Posts
Default

Swap your front and rear tires. If the shimmy changes then you know it's the wheels/tires. If it doesn't you need to look at driveline and steering.

In my experience any speed sensitive shimmy or wobble has always been a tire/wheel issue
Old 05-04-2016, 01:36 AM
  #4  
JK Jedi Master
FJOTM Winner
 
nthinuf's Avatar
 
Join Date: Jan 2008
Location: Austin <--> Colorado Springs
Posts: 11,465
Likes: 0
Received 162 Likes on 154 Posts
Default

Go up to the JK Write-Ups area. There is a diagnosis thread by Planman stuck right to the top...
Old 05-04-2016, 02:59 AM
  #5  
JK Junkie

 
kjeeper10's Avatar
 
Join Date: Jan 2013
Location: CT
Posts: 3,440
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Biginboca
Swap your front and rear tires. If the shimmy changes then you know it's the wheels/tires. If it doesn't you need to look at driveline and steering. In my experience any speed sensitive shimmy or wobble has always been a tire/wheel issue
X2 (10 char)
Old 05-04-2016, 01:09 PM
  #6  
JK Freak
Thread Starter
 
phljeeper's Avatar
 
Join Date: Aug 2009
Location: Philly Suburbs
Posts: 950
Likes: 0
Received 8 Likes on 4 Posts
Default

Originally Posted by kjeeper10
X2 (10 char)
Thanks guys. I know the planman writeup on wobbles. I have checked everything and all tight and good. The jeep only has 8k miles. I will try tires again.
Old 05-04-2016, 01:25 PM
  #7  
JK Enthusiast
 
Smudgeontheglass's Avatar
 
Join Date: Apr 2012
Location: Calgary, AB
Posts: 397
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by phljeeper
I have a 2015 two door with 2.5" Rock Krawler max travel with 35" trail grapplers. Rides great at city speeds and on the highway up to about 65. At 70 I get a shimmy. It feels like a tire balance issue but I have just had them re balanced and all good. Thoughts on what to check next?
I have a 2012 two door with a 2.5" Rubicon Express lift with 35" trail grapplers. I didn't have castor correction when I first lifted the Jeep but it drove perfectly fine with the stock BFG KOs. When I upgraded to a used set of the Nittos it had a very noticable wobble at around 70-80km/h. I upgraded my track bars to Adjustable JKS track bars and that helped a lot with the "flighty" steering feeling but I still had the same wobble. I did a 5 tire rotation and had no change in the wobble at that speed.

This spring I got gussets and a truss installed and to save some cash on the alignment I got some RE Geometry correction brackets. That moved my castor back to the 5-6 range and corrected the wobble problem completely.

I will eventually get better control arms but for now the brackets help a lot.

Last edited by Smudgeontheglass; 05-04-2016 at 01:34 PM.
Old 05-04-2016, 03:13 PM
  #8  
JK Freak
Thread Starter
 
phljeeper's Avatar
 
Join Date: Aug 2009
Location: Philly Suburbs
Posts: 950
Likes: 0
Received 8 Likes on 4 Posts
Default

Originally Posted by Smudgeontheglass
I have a 2012 two door with a 2.5" Rubicon Express lift with 35" trail grapplers. I didn't have castor correction when I first lifted the Jeep but it drove perfectly fine with the stock BFG KOs. When I upgraded to a used set of the Nittos it had a very noticable wobble at around 70-80km/h. I upgraded my track bars to Adjustable JKS track bars and that helped a lot with the "flighty" steering feeling but I still had the same wobble. I did a 5 tire rotation and had no change in the wobble at that speed. This spring I got gussets and a truss installed and to save some cash on the alignment I got some RE Geometry correction brackets. That moved my castor back to the 5-6 range and corrected the wobble problem completely. I will eventually get better control arms but for now the brackets help a lot.
Thanks. I do have a full set of Rock Krawler control arms and have the caster dialed in to about 6. I hope to try rotating and see if that helps. The tires have about 6k on them and have been rotated once.



Quick Reply: Thoughts on shimmy



All times are GMT -8. The time now is 04:02 PM.